Chris Grayling as justice secretary bothers me far less than he would in almost any other department. The legal profession has many years of experience in foiling, scotching, contradicting and plain ignoring the conference soundbites of politicians. I'll worry about Grayling's tough-guy pledges when I see the lord chief justice with his (metaphorical) glasses steamed up, and not before.

This is number three in the chart of all-time conference classics. At two, there's the abortion time-limit conversation, started by people with no intention of changing the law, but who just want to self-identify as the kind of politicians who seek a controlling interest in a stranger's uterus. At number one, "get tough on immigrants, especially the ones with cats", Theresa May's internet-generated content that she could have got from a website called www.theNigelFarage-izer.com. It's a bid to steal votes from Ukip, which in itself is classic tactics-over-strategy: people crunching numbers worry about the marginal effect of not being quite rightwing enough in closely contested constituencies with a potentially split vote. Nobody (apparently) is worrying about the more damaging effect of not being quite rational enough to appeal to the centre ground of any constituency. Anybody who wants to live out their lives without ever seeing another Conservative government will find this quite cheering.

The intruder debate – because it is so niche, so far to the fringes of life's tapestry, so completely unrelated to meaningful policymaking – I think of as almost poetic, the conference season's dream sequence. Parliamentary briefings on self-defence in your own home always refer to their figures as an "informal trawl" by the crown prosecution service. That's code for "we'd love to look more closely, but frankly there are so few of them that we cannot be arsed". Between 1990 and 2005, there were only seven prosecutions that resulted from a domestic burglary; less than one every two years. No wonder the Daily Mail gets so excited – to them, that's like seeing a comet.

To people who, considering its rarity, take little interest in self-defence as a political or social problem, it may come as a surprise to learn how much damage you are already allowed to inflict on an intruder. In 2009 Omari Roberts stabbed two teenaged intruders, one fatally, and the case against him was dropped; in September a couple shot two burglars and weren't charged. The law still takes a dim view of premeditated self-defence – so, for instance, if you lie in wait for a burglar, catch him, tie him up, throw him in a pit and set fire to him, you will be prosecuted. It's hard to fathom how you could, as suggested by Tory MP Priti Patel, "stop treating criminals like victims and victims like criminals" in a situation like that, without having an open-door policy on sociopaths.

If you think that sounds like an outlier, every case is an outlier. There is no normal in a crime that scarcely ever happens. At least with abortion and immigration, the figures are significant; it seems curious that a situation which so few people have ever encountered should ascend to the status of the "hot-button issue".

The last party conference to be dominated by this was Labour's in 2007, when Jack Straw promised to tighten the law as a "matter of urgency", despite the fact that it wasn't urgent, and when it came to it (the Criminal Justice and Immigration Act 2008), he merely codified it according to existing precedent, of which there was hardly any. The context for that was a Brownite regime that was petrified of tabloid sensibilities and had no confidence in its own ability to argue against them, as well as being atrophied by indecision over how best to play their honeymoon period. They were casting around to be as politically inclusive as reason would allow.

But even if Straw had changed the law to allow self-defence right up to the point where it's "grossly disproportionate", I doubt it would have made any practical difference. Most people don't have a gun; most people haven't been in a fight since they were at primary school. When the lord chief justice, Lord Judge, gave his opinion last month that the law was fine as it stood, he remarked: "I suspect if any of you have come home to find a burglar in your home, or have been in bed at night – or indeed having an afternoon snooze and found a burglar in your home – you are not calmly detached." Realistically, detachment aside, how fighting fit are you going to emerge from that snooze? What are the chances that your criminal opponent will be better at combat than you are?

This is not a practical suggestion. It is no blueprint for the protection of private property, nor even a metaphorical iteration of the power balance between victim and criminal. It's a statement of individual power against the flim-flam of civilisation. "We understand that society is all very well, but not if it comes at the price of being allowed to engage in hand-to-hand combat. We understand your God-given right to be superman, even if only in theory. We want to be superman too." The intruder scenario is conjured as individualistic wish-fulfilment by politicians with no confidence in the popularity and possibilities of government. It sounds bold, but it is actually insecure.